The present invention generally relates to aviation electronics, and more particularly concerns electronic systems for providing computing abilities to air crews, and even more particularly relates to an avionics computer system which has therein several independent subcomputer systems.
For years, pilots and members of the crew of airliners have been called upon to do numerous and various tasks that might be characterized as important, complicated and routine. Such tasks include calculating the fuel necessary to travel to an unscheduled landing spot, calculating the aircraft weight for determining compliance with airstrip restrictions, etc. Additionally, they are frequently looking through books to find and study the landing and taxiway configurations of many unfamiliar airfields. Recently, it has been proposed that the pilots and crew be provided with an Electronic Library System or ELS, which is a specially designed computer for the airliner crew. It has been proposed that this ELS contain the capability of providing a lower cost initial computer subsystem with the built in ability to add two more independent and identical computer subsystems.
It has been proposed that this be accomplished by providing a single ELS cabinet with three sectors therein with each sector being dedicated to accommodating a single computer subsystem. Each sector would include an equal number of slots for receiving line replaceable modules or LRMs. The LRMS would be processor modules and memory modules.
While this proposed electronic library system has received considerable acceptance in the industry, it does have several serious drawbacks.
First of all, the electronic library system with the three subsystems therein and where the total system is divided into three sectors with the same, or an arbitrarily predetermined, number of slots dedicated to each sector, has a fixed configuration. The problem with such an approach is that some users may desire to use the ELS for different purposes, which may not lend themselves to the fixed three subsystem approach. For example, one airline may wish to use the electronic library system to store electronically all runway maps of major airports in the U.S. This may require more memory than would be available to any one of the three independent dedicated subsystem as suggested.
Consequently, there exists a need for improvement in the electronic library systems where the independent computer subsystems are flexible within the fixed cabinet thereby allowing for increased user flexibility.